This two-volume set, CCIS 2274 and CCIS 2275, constitutes the refereed proceedings of the 39th National Conference on China Computer Federation, CCF NCCA 2024, held in Harbin, China, during July 15-18, 2024. The 48 full papers presented here were carefully reviewed and selected from 238 submissions. These papers are organized in the following topical sections: Part I: Artificial Intelligence and Applications; Data Science and Technology. Part II: Pattern Recognition & Machine Learning; Network Communication and Security; Frontier and Comprehensive Applications; Data Science and Technology.